This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The aim of this study is to investigate how different parts of the GI tract responds to HIV infection and subsequently to HAART treatment. Ultimately we hope to better understand the differential susceptibility of oral tissues compared to rectal mucosa to HIV infection. The proteomics core is investigating how the saliva proteome is different for HIV- and HIV+ individuals. The changes in the saliva proteome is also studied for HIV+ individuals before and after HAART treatment.